You also have access to here, which is the path to the directory
that the configuration file lives in. In this example, we point the
path variable to a file called data.csv inside of the same
folder as the configuration:

In larger projects, it’s useful to split the configuration up into
multiple files. Imagine you have a common config-data.py file and
several config-model-X.py type files, each of which use the same
data loader. When using multiple files, you must separate the
filenames by commas:
PALLADIUM_CONFIG=config-data.py,config-model-1.py.

If your configuration files share some entries (keys), then files
coming later in the list will win and override entries from files
earlier in the list. Thus, if the contents of config-data.py are
{'a':42,'b':6}” and the contents of config-model-1.py is
{'b':7,'c':99}, the resulting configuration will be {'a':42,'b':7,'c':99}.

Even with multiple files, you’ll sometimes end up repeating portions
of configuration between files. The __copy__ directive allows you
to copy or override existing entries. Imagine your dataset loaders
for train and test are identical, except for the location of the CSV
file: